A few years ago, in one of those too frequent attempts to create a list of best films by genre, The Exorcist was voted the scariest film ever made. In this case, I think they got it right. The special effects, which still appear gruesome, prompted theaters to issue barf bags, but the visual gags play a miniscule part in the film’s enduring legacy. What makes The Exorcist so horrifying is the way the film domesticates the supernatural, tossing a young girl around a comfortable home — and for most of the film, her bedroom — under the influence of demonic evil. This isn’t Friday the 13th, where a trip to the lake will get you slashed; The Exorcist is about a massive violation of innocence and the spaces the innocent call home. Film critic Stanley Kauffman, writing of The Exorcist, said, “This is the most scary film I’ve seen in years ­ the only scary film I’ve seen in years,” apparently including Rosemary’s Baby.

Paranormal Activity, the debut film by Oren Peli, is a low-budget, secularized version of The Exorcist. It is easily the most frightened I’ve been at the movies in years, excluding the existential dread that overcame me during Terminator: Salvation. Like other films to make use of the “found footage” conceit — that is to say, the taped recordings left behind following the purported events — Paranormal Activity should be approached with a minimum of preparation and, if possible, a minimum of hype. Since by now I’ve contributed to enhancing the latter, I’ll balance this by revealing a minimum of plot. The film takes place at the home of Katie (Katie Featherston), a student, and Micah (Micah Sloat), a day trader, who live together in a bland tract home in suburban San Diego. Katie, we soon learn, who has been gently haunted for years, is now experiencing a recurrence of symptoms. Micah, who initially has his doubts, buys a camera to record the nightly paranormal activity in their bedroom; later, his doubt erased, he attempts to confront the entity directly. Things, as you might expect, end badly.

While Katie’s performance is stunningly natural, her sweetness and innocence undercutting a lifetime of horrors, it is Micah who drives the story. Despite repeated warnings not to engage whatever might be haunting Katie, he is constantly in an offensive position, waging war on their unseen guest. If you’re like me, you’ll have little patience for Micah — for one thing, his name rhymes with paprika — but his insecurity is crucial to the events of the film, as is his overwhelming arrogance. As in The Exorcist, the demon in Paranormal has no need for the crude implements of the hacker-and-stabber set: Why lift a chainsaw if your mere existence causes paralyzing fear? Instead, by focusing on a single girl, it terrorizes the spirit of everyone it contacts, inducing or deepening various crises of faith — before Micah, it was Father Damien, the broken man who just lost his mother — until the fear with which they regard the world is turned against them, with disastrous results. Paranormal succeeds for all the reasons The Exorcist does and, during a few key moments — one of which is the final scene, sadly — slides into camp just like The Exorcist can, completely killing the mood in the process. Despite that, it’s a terrifically conceived movie, frightening us more by what it doesn’t show than by what it does. To echo Stanley Kauffman, it’s by far the scariest film I’ve seen in years.